Plant Sea Holly (Eryngium) and You'll Be Happy to Have the "Blues"

Dorothy is a former newspaper reporter and the author of several books. Michael is a professional landscape/nature photographer.

Big Blue Sea Holly (Eryngium zabelii) | Source

Sea Holly Can Be Rare...and Blue!

When planning your flower garden, wouldn't it be nice to have something rare and unusual to show off to your neighbors? You can do just that if you plant Sea Holly flowers, as you can see from the photographs. Some of them are the rarest color available - blue - and once you plant them, they are so easy to maintain, requiring very little care. The Big Blue Sea Holly (Eryngium zabelii) is my personal favorite with its steel blue prickly flowers laying atop a beautiful mound of silvery blue leaves.

But, when it comes to Sea Holly, the initial planning is very important because they have tap roots that, although they can grow deep into the ground and find water where other plants can't, don't like to be disturbed once planted. Wherever you plant them, that's where they need to stay. Kathy Wolfe of the Washington State University Extension Service wrote a great paper on roots called The Hidden World of Roots.

Sea Holly plants love sunshine and normal or sandy soil and, once established, they are extremely drought resistant.* Keep in mind that they will grow to almost three feet high and have a spread of about 24 inches, so plant them where they will have adequate room and access to plenty of sunshine.

You will need to cut back the old stems to ground level, preferably in late fall (although you could wait until early spring, which won't be too late should you forget in the fall). They should come back with a vengeance, then provide you with bright blooms all summer long.

*Note: In long periods of drought, however, you will still want to make sure they get adequate water.

Big Blue Sea Holly (Eryngium zabelii) | Source

Beautiful Even Before It Develops Its True Color

Flat Sea Holly (Eryngium alpinum) bud

Many Different Species of Sea Holly Are Available

Most nurseries should have several different species of Eryngium, which have been cultivated as garden plants; and most of the sea holly species are considered as perennials in USDA Hardiness Zones 4 - 9. This is a brief overview of some of the most common ones you might find available, listing both the common name and the botanical name:

Flat Sea Holly (Eryngium alpinum) – This species is native to Eastern Europe, growing two to three feet tall with silvery-blueish-green flower heads which protect the plant from negative effects of overexposure to sun radiation.

Alpine Sea Holly (Eryngium planum) – This plant will grow to about two feet high; it is a native plant in Switzerland.

Amethyst Sea Holly (Eryngium amethystinum) – This native European plant is one of the most cold hardy in this particular genus, but it likes a calcium-rich soil to thrive. It will grow to about a foot to a foot and a half high showing gorgeous light blue to purple flowers, thus the name.

Mediterranean Sea Holly (Eryngium bourgatii) – You will need well-drained soil and plenty of sun for this attention-getting plant, which is a native to Pyrenees and Morocco. The flowers are a blue-green color, making it extremely popular in container gardens as well.

Common Sea Holly (Eryngium maritimum) – Unlike most of the others, the Common Sea Holly plant is one of the smallest of the species, only growing from about six to 18 inches tall.

Giant Sea Holly (Eryngium giganteum) - If you plant this one, you'll want to put it in the back of your garden, as it may require staking and it will grow from three to four feet (or even higher). This plant is also known as Miss Willmot's Ghost, having been named for Ellen Willmot, the English horticulturist who was one of the first 60 recipients of the Victorial Medal of Honor in 1897, awarded by the Royal Horticultural Society Council to those it considered deserving of special recognition.

Rattlesnake Master (Eryngium yuccifolium) – Native Americans used this flower as an antidote to rattlesnake bites and that's how it got its name. It is native to the eastern United States and has button-like flowers in a pale chartreuse color (somewhere between yellow and green). It will, like some of the other Eryngium species, grow from two to six feet tall, so if you choose this one, be prepared to stake it and put it in the back of the garden, as it will tower above most of your other flowers.

Big Blue Sea Holly (Eryngium zabelii) | Source

The Rattlesnake Master

Eryngium yuccifolium (Rattlesnake Master) | Source

Flat Sea Holly (Eryngium alpinum)

Eryngium alpinum (Flat Sea Holly)

Eryngium giganteum (Giant Sea Holly)

Eryngium giganteum (Giant Sea Holly) | Source

Questions & Answers

Questions must be on-topic, written with proper grammar usage, and understandable to a wide audience.

Question:

my Eryngium is supposed to be zabelli, but it has green leaves, so is it?

Answer:

It could be, as zabelli tends to have more green than other varieties. If the center part is completely green as well, it probably is zabelli.

Comments

No HTML is allowed in comments, but URLs will be hyperlinked. Comments are not for promoting your articles or other sites.

sending

AUTHOR

Mike and Dorothy McKenney

3 months agofrom United States

Paul, can you tell me what type of sea holly you planted. Some of them are naturally grey-green color, although I wasn't aware of them turning blue, and then turning back to the original color. Let me know and I'll do some serious research. Thanks!

PaulBrennan

3 months ago

I planted a sea holly in the front garden (with lots of compost into a clay soil and lots of sun). After a few days, and as expected, the flowers and petals turned from grey-green to a beautiful shiny blue. Now, a few weeks later the blue colour has disappeared and it's back to the original grey-green...Any ideas as t what's happening???

AUTHOR

Mike and Dorothy McKenney

17 months agofrom United States

Intriguing is a good word for these, indeed. Thanks for stopping by.

Emily Lantry

17 months agofrom Tennessee

I've never heard of this plant, but I am so intrigued! I really want to find some. Thank you so much for sharing!

Beautiful pictures! I have 2 sea hollies in my garden. I love the luminous blue/green hue. But now that shade is taking over, I worry that they will become unhappy. I have moved sea holly before as well as other plants people say you can't move. I wait until the plant is dormant in winter and dig them up with a large clump of the surrounding soil. I dig deep as well. This has worked for several plants.

Connect with us

This website uses cookies

As a user in the EEA, your approval is needed on a few things. To provide a better website experience, dengarden.com uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

This is used to display charts and graphs on articles and the author center. (Privacy Policy)

Google AdSense Host API

This service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)

This is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)

Facebook Login

You can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)

Maven

This supports the Maven widget and search functionality. (Privacy Policy)

We may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.

Conversion Tracking Pixels

We may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.

Statistics

Author Google Analytics

This is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)

Comscore

ComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)

Amazon Tracking Pixel

Some articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)